SmogRank / United States / Illinois / Peoria
Peoria, month by month
Peoria, Illinois has a measured daily mean on 1,208 days since 10 January 2023. Its worst month was June 2025, at 63 US AQI (15.7 µg/m³), 386th of 2,508 cities on that month's world ranking. Its cleanest was April 2024, at 27 US AQI (4.8 µg/m³). 2025 averaged 51 US AQI (9.3 µg/m³), against 41 US AQI (7.3 µg/m³) in 2024.
Every month since 2023
The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales
Months without a mean, and why
6 months
| Month | Why |
|---|---|
| Jul 2023 | 7 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 23 with under 18 hours of readings or readings that failed our checks. |
| Jun 2023 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| Apr 2023 | 16 of 30 days measured; a month needs 21. The others: 3 missing from OpenAQ's archive, 11 with under 18 hours of readings or readings that failed our checks. |
| Mar 2023 | No day measured. The others: 20 missing from OpenAQ's archive, 11 with under 18 hours of readings or readings that failed our checks. |
| Feb 2023 | 3 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive. |
| Jan 2023 | 16 of 31 days measured; a month needs 22. The others: 6 missing from OpenAQ's archive. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Peoria's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| June 2025 | 6315.7 µg/m³ | 386thof 2,508 | Northern United States and Canada, June 2025 Northern United States and Canada, May and June 2025 |
| July 2026 | 6315.3 µg/m³ | 503rdof 2,784 | Northern United States and Canada, July 2026 |
| August 2023 | 5812.9 µg/m³ | 272ndof 1,980 | – |
| July 2025 | 5712.3 µg/m³ | 768thof 2,889 | North-eastern United States and Canada, 29 July to 9 August 2025 |
| August 2025 | 5612.0 µg/m³ | 768thof 2,901 | North-eastern United States and Canada, 29 July to 9 August 2025 |
| May 2023 | 5410.8 µg/m³ | 373rdof 1,600 | – |
Monthly means over the days measured; finished months only. World rank: its place on that month's world ranking of every city with enough days. Each month opens that ranking.
Peoria's worst days
| Day | US AQI | Episode |
|---|---|---|
| 19 Jul 2026 | 16373.3 µg/m³ | Northern United States and Canada, July 2026 |
| 1 Aug 2025 | 15561.5 µg/m³ | North-eastern United States and Canada, 29 July to 9 August 2025 |
| 31 Jul 2025 | 15257.1 µg/m³ | North-eastern United States and Canada, 29 July to 9 August 2025 |
| 20 Jul 2026 | 12746.1 µg/m³ | Northern United States and Canada, July 2026 |
| 5 Jun 2025 | 11943.0 µg/m³ | Northern United States and Canada, May and June 2025 |
| 6 Jun 2025 | 11139.7 µg/m³ | Northern United States and Canada, May and June 2025 |
| 7 Jun 2025 | 9733.7 µg/m³ | Northern United States and Canada, May and June 2025 |
| 25 Jul 2023 | 9331.6 µg/m³ | Northern United States and Canada, July 2023 |
| 21 Feb 2024 | 8929.3 µg/m³ | – |
| 15 Mar 2025 | 8728.3 µg/m³ | Eastern United States, March 2025 |
Daily means, the highest since 10 Jan 2023; the WHO's daily guideline is 15 µg/m³. Each date opens that day's world ranking, and each episode the bad-air spell it was part of.
Use this history
SmogRank, PM2.5 monthly and daily means, Peoria, Illinois, United States, 10 Jan 2023 – 11 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/us/peoria-illinois/history (accessed 13 Oct 2026).
You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.
Peoria now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-13 02:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some low-cost readings: Sensor.Community, ODbL (data and licence). Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver), no reuse terms published (why we use them).